iOS - _OBJC_CLASS_$_CTTelephonyNetworkInfo not found?
I had a similar issue. Mine was related to having multiple targets, where it would fail on only 1 target.
To resolve it I had to ctrl-click the CoreTelephone.framework and select to add it to all my schemes.
The exact error I was getting was "Undefined symbols for architecture i386: "_OBJC_CLASS_$_CTTelephonyNetworkInfo","